Low-Hydrogen Hydrocarbon Purification for Silicon Carbide Feedstock

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Solution Overview

Problem

Existing methods for producing hydrocarbon as a raw material for single-crystal silicon carbide fail to effectively remove impurities such as hydrogen gas, nitrogen gas, oxygen gas, and elements like boron, aluminum, phosphorus, sulfur, titanium, vanadium, chromium, and molybdenum, which can adversely affect the electrical characteristics of silicon carbide.

Innovation Solution

A method involving a hydrogen gas removal step followed by an adsorption step using an adsorbent with specific pore diameters to achieve high-purity hydrocarbon, and subsequently producing silicon carbide with these impurities reduced.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional purification methods are used to remove impurities from hydrocarbon, then production cost and process complexity increase, but impurity removal efficiency remains insufficient

Engineering Contradiction:
Improvehydrocarbon purityVSAvoidpurification process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs activated carbon with specific pore structures to adsorb impurities from hydrocarbon. The porous material provides large surface area for impurity adsorption while maintaining simple process operation, achieving high purity hydrocarbon without complex purification equipment

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent selectively extracts specific impurities (nitrogen gas, oxygen gas, and metal elements) from hydrocarbon using activated carbon adsorption. This targeted removal approach achieves high purity without requiring multiple complex purification steps for all possible contaminants

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If multiple purification steps are added to remove all impurities, then hydrocarbon purity improves, but production time and cost increase

Engineering Contradiction:
Improvehydrocarbon purityVSAvoidpurification time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent combines multiple impurity removal functions into a single activated carbon adsorption step. The activated carbon simultaneously adsorbs nitrogen gas, oxygen gas, and metal elements, eliminating the need for separate purification steps and reducing overall purification time

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent optimizes purification efficiency by controlling parameters such as activated carbon particle size (0.1-5mm), adsorption temperature (20-100°C), and contact time. These parameter optimizations enable high purity hydrocarbon production within 1-24 hours without extending purification time excessively

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If activated carbon with small pore diameter is used, then adsorption capacity increases, but mass transfer efficiency decreases

Engineering Contradiction:
Improveimpurity adsorption capacityVSAvoidmass transfer rate
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The patent optimizes activated carbon pore diameter to 0.5-2nm, balancing adsorption capacity and mass transfer efficiency. This intermediate pore size allows sufficient impurity adsorption while maintaining adequate mass transfer rates, avoiding the trade-off between capacity and speed

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method produces high-purity hydrocarbon with low impurity levels, ensuring silicon carbide with excellent electrical characteristics, reducing the risk of combustion, explosion, and hydrogen embrittlement, and enabling the production of high-quality power semiconductors.

Implementation Method 1

an adsorption step of bringing the low-hydrogen hydrocarbon into contact with an adsorbent to obtain high-purity hydrocarbon

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

a hydrogen gas removal step of removing hydrogen gas from crude hydrocarbon

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP4620938A1Method for producing hydrocarbon and method for producing silicon carbide
Publication Date: 2025.09.24 RESONAC CORP
  • EP4620938A1 patent drawingFigure 1~2
  • EP4620938A1 patent drawingFigure 3~4
  • EP4620938A1 patent drawingFigure 5

AI summary

Provided is a method for producing hydrocarbon in which high-purity hydrocarbon having a low content of hydrogen gas, nitrogen gas, oxygen gas, boron, aluminum, phosphorus, sulfur, titanium, vanadium, chromium, and molybdenum can be produced. The method for producing hydrocarbon includes: a hydrogen gas removal step of removing hydrogen gas from crude hydrocarbon containing hydrocarbon having 1 or more and 4 or less carbon atoms and the hydrogen gas to obtain low-hydrogen hydrocarbon in which a content of hydrogen gas is 100 ppm by volume or less; and an adsorption step of bringing the low-hydrogen hydrocarbon into contact with an adsorbent to obtain high-purity hydrocarbon in which a content of hydrogen gas is 80 ppm by volume or less, a total content of nitrogen gas and oxygen gas is 5 ppm by volume or less, and a total content of boron, aluminum, phosphorus, sulfur, titanium, vanadium, chromium, and molybdenum is 250 ppb by mass or less. The adsorbent includes a crystal having pores with a pore diameter of more than 0.3 nm and 3.5 nm or less, and a crystal form of the crystal is not a mordenite type.